Biomonitoring of Acetylcholinesterase (AChE) Activity among Smallholder Horticultural Farmers Occupationally Exposed to Mixtures of Pesticides in Tanzania

Application of the theory of planned behavior to model the intention and behavior of tomato growers in pesticide exposure

Widespread and indiscriminate use of pesticides has become one of the most important environmental and public health problems around the world. This study was conducted with the aim of applying the theory of planned behavior model to investigate the knowledge, attitude, and behavior of tomato growers in the face of pesticides in agricultural lands located in Kurdistan province, western Iran. We included 300 tomato growers in this study and they filled up a standard TPB questionnaire containing questions about basic information, knowledge, attitude and behavior about pesticides and their actions for disposing of the residual spray solution, washing place of pesticide sprayer, and the disposal of water from washing the equipment. Most of the respondents, 86.7 %, had not participated in promotional classes on how to dispose of the residual solution. Approximately 46.15, 38.46, and 15.39 % of pesticides contained moderately toxic, slightly toxic and practically non-toxic compounds, respectively. More than two-thirds (89 %) of the tomato growers stated that they leave the water from washing the equipment in the field. In addition, among the three variables of TPB, attitudes had the highest score (3.38), which indicated the positive to relatively neutral attitude of farmers towards the safe use of pesticides. These findings can be useful for planners and environmental organizations to make effective interventions to reduce environmental pollution caused by pesticides. Since the incorrect use of pesticides is one of the important environmental and health factors, education and awareness programs can help farmers to consider the correct use of pesticides and environmental protection more.

Evaluation of genotoxic effects in workers and residents of rural areas exposed to pesticides in Brazil

Brazil is one of the world's largest consumers of pesticides. This intense use impacts the environment and exposes a wide range of individuals to pesticides, including rural workers who are occupationally exposed and rural residents who are environmentally exposed. We aimed to evaluate the effects of occupational exposure to pesticides on the health of rural workers and rural residents. We conducted an epidemiological study with 104 farmers and 23 rural residents of Casimiro de Abreu (Rio de Janeiro, Brazil). A comparison group (urban residents) comprised 103 residents of the urban area of the same city. We determined the activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) using a modified version of Ellman's method to evaluate exposure. In addition, we performed genotoxic and mutagenic analyses with the comet assay and the cytokinesis-block micronucleus (CBMN) assay. There was a reduction in cholinesterase activity, mainly BChE, in rural workers and rural residents compared with urban residents (p = 0.002). There was an increase in genotoxic effects in rural workers compared with urban residents (comet assay, p < 0.001; CBMN assay, p < 0.001). In addition, there was a greater chance of genotoxic changes in rural workers exposed to pesticides based on the comet assay (odds ratio [OR] 7.6, 95 % confidence interval [CI] 6.6-15.9) and the CBMN assay (OR 22.7, 95 % CI 10.3-49.9). We found that individuals occupationally exposed to pesticides are more likely to have genotoxic effects. These findings are useful for the development of programs to monitor populations exposed to genotoxic substances and allow the development of strategies for the prevention, control, and surveillance of effects that result from occupational and environmental exposures to pesticides.

Physical function as a marker to assess the effects of occupational long-term pesticide exposure

In this cross-sectional study, we determined the relative impact of long-term occupational exposure to pesticides on physical performance and perception of tiredness. Experimental data was collected in locus from agricultural communities and included surveys to assess the duration of exposure to pesticides, social status, habitual physical activity levels, presence of common mental disorders (CMD), and self-reported tiredness. Plasmatic cholinesterase (PChE), body composition and traditional functional performance tests (Handgrip strength-HGS; Time up and go-TUG; and Sit-to-stand-STS) were obtained. From the 127 individuals tested, cluster analysis yielded 80 individuals divided in Direct Exposed (n = 37) and Indirect Exposed (n = 43); Tired (n = 16), and Not Tired (n = 64). PChE values were within the reference values (5209.64-13943.53 U/L). Pesticide exposure had no influence on PChE levels, CMD or fatigue (p > 0.05), while Self-reported tiredness had (p < 0.05). Principal Component Analyses showed that HGS; STS and TUG (i.e., physical performance variables) are negatively influenced by two independent factors: pesticide exposure and self-reported tiredness. We conclude that chronic pesticide exposure and tiredness can negatively impact physical performance, independently, without clinically significant changes in PChE levels that is a biomarker used to track pesticide intoxication. Functional physical tests can be a useful tool to identify chronic pesticide exposure, and help with the limitations of commonly used parameters (i.e. PChE and CMD). Self-reported tiredness is a confounding variable.

Relationship Between Pesticide Exposure Factors and Health Symptoms Among Chili Farmers in Northeast Thailand

OBJECTIVES

The unsafe use of pesticides in agriculture represents a major hazard to human health. This study was conducted to investigate the association between pesticide exposure and health symptoms among chili farmers in northeast Thailand.

METHODS

This cross-sectional analytic study included 141 chili farmers in Sakon Nakhon Province, in northeast Thailand. Data regarding health symptoms were gathered using a self-report questionnaire. A medical technician tested blood cholinesterase activity using an erythrocyte method, and an occupational medicine specialist at Ramathibodi Hospital in Bangkok, Thailand reviewed the results. Associations between personal characteristics, pesticide exposure factors, and health symptoms were analyzed using multiple logistic regression.

RESULTS

Of the 141 chili farmers studied, 66.7% experienced pesticide poisoning, as indicated by below-normal cholinesterase levels. Fatigue was the most frequently reported symptom associated with pesticide exposure, affecting 37.6% of participants. This was followed by nausea and vomiting (31.9%), dizziness (14.9%), and dry throat (14.9%). Multivariate logistic regression analysis revealed that several factors were significantly associated with adverse symptoms: amount of work experience, volume of pesticides used, use of chemical pesticides, use of leaking containers during spraying, direct pesticide exposure while working, contact with pesticide-soaked clothing, consumption of food and drinks in the fields, and blood cholinesterase level indicating risk.

CONCLUSIONS

This study suggests potential health risks for chili farmers stemming from exposure to and contamination by pesticides used in agricultural practices. To mitigate these risks, it is essential to supply personal protective equipment and to implement educational programs aimed at improving protective behaviors among farmers.

Investigation of the Relationship between Spontaneous Abortion, Serum Pesticides, and Polychlorinated Biphenyl Levels

Occupational and environmental chemical exposure have been associated with adverse reproductive consequences. This study investigates the relationship between spontaneous abortion and blood pesticide and polychlorinated biphenyl (PCB) levels. A survey was conducted, and blood samples were collected from 200 patients, consisting of 100 cases with spontaneous abortion and 100 cases with normal deliveries. A total of 150 different pesticides, including organophosphates, organochlorines, carbamates, and pyrethroids, were screened in the collected blood samples and analyzed quantitatively using Tandem mass spectrometry-specifically in combination with liquid chromatography and gas chromatography-tandem mass spectrometry methods. Eight types of PCBs were analyzed with the gas chromatography-tandem mass spectrometry method. The groups were compared based on these analyses. The mean age of the participants was 28.09 ± 4.94 years. In 59% of the spontaneous abortion group, 5.05 ± 1.97 chemicals were detected in different amounts. (p < 0.05). Analysis of the samples identified the presence of β-Hexachlorocyclohexane (β-HCH), delta-hexachlorocyclohexane (δ HCH), Hexachlorobenzene (HCB), Pentachlorobiphenyl-28 (PCB-28), Pentachlorobiphenyl-52 (PCB-52), o,p'-Dichlorodiphenyldichloroethylene (o,p'-DDE), p,p'-Dichlorodiphenyldichloroethylene (p,p'DDE), o,p'-Dichlorodiphenyldichloroethane (o,p'-DDD), p,p'-Dichlorodiphenyldichloroethane (p,p'-DDD), Pentachlorobiphenyl-118 (PCB-118), Pentachlorobiphenyl-101 (PCB-101), Pentachlorobiphenyl-153 (PCB-153), Pentachlorobiphenyl-138 (PCB-138), Pentachlorobiphenyl-202 (PCB-202), Pentachlorobiphenyl-180 (PCB-180) as well as Fibronil, Buprimate, Acetoclor, Acemiprid, Pentimanthalin, and Triflokystrobin. The spontaneous abortion group had significantly higher exposure to PCB-101, PCB-52, PCB-138, and δ-HCH (p < 0.05). Women included in the study had high pesticide and PCB exposure rates. Many of the blood samples contained multiple pesticides with endocrine-disrupting effects. Higher exposure to organochlorine compounds in the serum was identified in the group with spontaneous abortions.

Comparison of acetylcholinesterase among employees based on job positions and personal protective equipment in fuel station

The purpose of this study was to compare the levels of acetylcholinesterase (AChE) among employees based on job positions and the wearing of personal protective equipment (PPE) in fuel station areas. The sample group consisted of 200 people sorted into various groups, including (i) Inside fuel dispenser area (I-FDA) group consisting of 100 employees for refueling, cashier, and loading fuel into storage tanks, and (ii) Outside fuel dispenser area (O-FDA) group, consisting of 100 employees working in convenience stores, food stores, coffee shops, and offices, as well as general staff and car washers. Data were collected using interview questionnaires and blood samples were analyzed for AChE activity. The results showed that the I-FDA group had a significantly lower mean of serum AChE (7.38±1.73 U/ml) than the O-FDA group (7.85±1.49 U/ml) (p<0.05). The I-FDA group had a 2.43 times higher risk of abnormal serum AChE than the O-FDA group (OR=2.43, 95%CI=1.05-5.60). When considering the risk factors for job positions, it was found that refueling and cashier positions had lower AChE activity levels than those who did not (p<0.05). In the part, employees for food sales in a closed building and those wearing PPE masks had significantly higher AChE activity levels than those who did not or who wore them (p<0.05). Based on the aforementioned, employers at fuel stations should strictly determine the appropriate measures for wearing a PPE mask. Further, employees should be provided accommodation away from oil supply or enclosed buildings during breaks to reduce the effects on the neurotransmitter.

The determinants of thyroid function among vegetable farmers with primary exposure to chlorpyrifos: A cross-sectional study in Central Java, Indonesia

Objectives

Occupational pesticide exposure, chlorpyrifos (CPF) in particular, may adversely affect the thyroid. The purpose of this study was to evaluate the determinants of thyroid function as indicated by the serum concentration of thyroid-stimulating hormone (TSH) among Indonesian vegetable farmers with primary exposure to CPF.

Methods

A total of 151 vegetable farmers participated in this study. The sociodemographic and occupational characteristics of the participants were obtained using a structured interviewer-administered questionnaire. A validated quantitative method was used to estimate the cumulative exposure level (CEL). Serum TSH, thyroglobulin (Tg), free thyroxine (FT4), and urinary iodine excretion (UIE) were measured in the laboratory. The difference in TSH concentrations according to CEL and other characteristics were analysed using the Mann-Whitney U test. A multiple linear regression model was used to evaluate the potential determinants of TSH.

Results

The mean age was 50 (SD 9.4) years. The median concentrations of TSH, FT4, and Tg/FT4 ratio were 1.46 mIU/L, 1.17 ng/dL, and 6.23 × 10², respectively. We observed that higher TSH concentrations were found among those with a higher Tg/FT4 ratio, were classified as high CEL, and had lower UIE or FT4.

Conclusions

Our findings show that Tg/FT4 ratio, CEL, FT4, UIE concentrations, and post-spraying days were determinants of TSH concentrations among farmers with primary exposure to CPF. These results indicate that farmers are exposed to agents with thyroid-disrupting properties, thus supporting previous evidence showing the potential for thyroid disorders in agricultural populations exposed to pesticides.

The impact of the use of personal-protective-equipment on the minimization of effects of exposure to pesticides among farm-workers in India

Introduction

Although excessive use of pesticides and unsafe agricultural practices may contribute to numerous intoxications, the role of PPE (personal-protective-equipment) in the minimization of toxicological effects due to pesticide exposure has not been addressed so far. The present study aimed to assess the impact of the use of PPE on the minimization of effects of exposure to pesticides among farm-workers.

Methods

A community-based follow-up study with questionnaire-based survey and field observations was undertaken among farm-workers (n = 180) of Rangareddy district, Telangana, India. Biomarkers of exposure such as cholinesterase activity, inflammatory markers (TNF-α, IL-1β, IL-6, cortisol, and hs-C reactive protein), nutrients (vitamins A, E), liver function (total protein and A/G ratio, AST and ALT levels) were investigated in the laboratory by following the standard protocols.

Results

Farm-workers who had a mean farming exposure of 18 years of and who neither followed safe pesticide handling practices nor used PPE and also showed reluctance to obey good agricultural practices (GAPs). Inhibition of AChE (acetylcholine esterase) with increased inflammation was found among farm-workers as compared to their respective normal values when they have not used PPE. Linear regression statistical analysis revealed a profound effect on inhibition in the AChE activity and various inflammatory markers with the increase in the duration of pesticide exposure. Further, there was no effect of the duration of pesticide exposure on the levels of vitamins A, E, ALT, AST, total protein, and A/G ratio. Further, intervention studies carried out on the use of PPE provided (commercially available and cost-effective) for 90 days showed a significant reduction in the biomarker levels (p < 0.01).

Conclusion

This study demonstrated the importance of the use of PPE during pesticide applications and other agricultural tasks to minimize pesticide-associated adverse health effects.

Multibiomarker approach in fish to assess a heavily polluted Brazilian estuary, Guanabara Bay

Brazil's Guanabara Bay (GB), located in Rio De Janeiro, is a deeply contaminated, eutrophic waterbody that challenges the understanding of the effects of pollutants on the biota. This paper presents a strategy to evaluate the impact of contamination utilizing a multibiomarker approach in two fish species: corvine (Micropogonias furnieri) and burrfish (Chilomycterus spinosus). The strategy is comprised of a general biomarker of fish' physical condition, the condition factor (CF), and specific biomarkers of pollutant exposure such as acetylcholinesterase (AChE), metallothionein (MT) activity and biliary polycyclic aromatic hydrocarbons (PAH) metabolites. Our results indicate that fish from GB are greatly affected by environmental pollution. CF values were lower in fishes from GB than in the reference site indicating that these fishes were under higher environmental stress. Lower AChE activity level in both species showed vulnerability to the presence of pesticide residues. Higher levels of MT in both species in GB reflect the consequences of heavy metal exposure in the bay, in spite of their bioavailability being restricted specially by the high organic matter content of GB. The levels of PAHs were higher in GB for both fish species, indicating exposure to these substances. However, the fish species showed different behavior regarding the origin of the PAHs. The multibiomarker approach used in this study evidently depicted effects on the health of fish in a waterbody with a complex polluted situation and further categorized the effects of anthropogenic activities in this aquatic system.

Quercetin-3-O-β-D-Glucopyranoside-Rich Fraction from Spondias mombin Leaves Halted Responses from Oxidative Stress, Neuroinflammation, Apoptosis, and Lipid Peroxidation in the Brain of Dichlorvos-Treated Wistar Rats

Dichlorvos (2,3-dichlorovinyl dimethyl phosphate or DDVP), is a popular organophosphate (OP) with several domestic, industrial, and agricultural uses and applications in developing countries [...].

Characterization of Farmer’s Knowledge and Management Practices of Papaya Mealybug Paracoccus magnatus (Hemiptera: Pseudococcidae) in Tanzania

Papaya mealybug (PMB) is a serious insect pest for papaya production in Sub-Saharan Africa, limiting production potential in farming communities. We did a household survey to evaluate the Characteristics of farmers' knowledge, challenges, and current (PMB) control practices in four papaya growing regions of Tanzania namely, Tanga, Dodoma, Pwani, and Katavi involving 100 papaya farmers. The study found that 96% of farmers reported PMB, as a major challenge in papaya production. Very few (0.8%) of the farmers were knowledgeable on insect pest identification. Chemical pesticides were the only option for PMB control, and 43.0% of farmers were able to access and apply. We also found that 36.4% of the farmers were aware of the adverse effects of chemical pesticides. Furthermore, the study observed that 0.3% of farmers use botanical pesticides. Additionally, the study observed that 44.1% of farmers use control measures against PMB, the remaining 55.9% did not practice any control measure, thus leading to low papaya yields observed in the study regions. Our findings provide insights to farmers into the use of plant-based pesticides, mainly plant essential oils, and its benefits that may promote farmers' attitudes towards increasing papaya yield and reducing chemical pesticide use to avoid pest resistance.

Pesticide Spraying and Reduced Cholinesterase Activity among Hill Tribe Farmers in Thailand

BACKGROUND

Farming is an important occupation in Thai hill tribe communities, which are often remote, and lack other economic opportunities along with basic educational, health care, and occupational health and safety services. Additionally, these communities have a unique culture and language.

OBJECTIVES

The present study was conducted in northern Thailand to evaluate pesticide exposures and associated health impacts among hill tribe farmers, and to compare them to Thai farmers.

METHODS

Lahu hill tribe farmers in a mountain community were recruited by public health hospital staff, along with a reference group of lowland Thai farmers. Participants completed a survey on demographic factors and work practices, and blood and urine samples were collected by a trained nurse. Acetylcholinesterase activity (AChE) was quantified to assess pesticide exposure, whereas liver and kidney functions were evaluated using clinical biomarkers.

RESULTS

A large fraction (nearly 50%) of Lahu farmers were illiterate and could not speak Thai. Thai farmers worked fewer hours per week (39.4) than did Lahu farmers. Among Lahu farmers, AChE levels were significantly lower (worse) than those of Thai farmers. However, other health outcomes in these populations were similar. Formal education and language skills were not associated with pesticide exposures or health outcomes. Pesticide spraying was found to be a significant predictor of reduced AChE (OR=8.5, 95% CI 1.1-69.6).

CONCLUSIONS

Pesticide exposures are a significant occupational health hazard among Thai hill tribe farmers. Training, potentially delivered by community health volunteers, is needed to communicate safe pesticide work practices to these farmers.

PARTICIPANT CONSENT

Obtained.

ETHICS APPROVAL

The study protocol was approved by the Institutional Review Board of Mae Fah Luang University (REH-61080).

COMPETING INTERESTS

The authors declare no competing financial interests.

Cumulative exposure characteristics of vegetable farmers exposed to Chlorpyrifos in Central Java - Indonesia; a cross-sectional study

Background

Agriculture is a major economic sector in Indonesia. Chemical pesticides are widely being used in agriculture for controlling pest. There is a growing concern that pesticide exposure, particularly chlorpyrifos (CPF) exposure, combined with other occupational characteristics that determine the level of exposure, can lead to further health impacts for farmers. Our objective was to evaluate the cumulative exposure characteristics among farmers exposed to CPF by using a validated algorithm.

Methods

We conducted a cross-sectional study of 152 vegetable farmers aged 18–65 who actively used CPF for at least 1 year in Central Java, Indonesia. Subject characteristics were obtained using a structured interviewer-administered questionnaire, addressed for sociodemographic and work-related characteristics. The cumulative exposure level (CEL) was estimated as a function of the intensity level of pesticide exposure (IL), lifetime years of pesticide use and the number of days spraying per year. CEL was subsequently classified into two groups, high and low exposure groups. The difference in characteristics of the study population was measured using Chi-square, independent-t or Mann-Whitney test. Association between CEL and its characteristics variables were performed by multiple linear regression.

Results

Seventy-one subjects (46.7%) were classified as the high exposure group. The use of multiple pesticide mixtures was common among our study population, with 94% of them using 2 or more pesticides. 73% reported direct contact with concentrated pesticides product, and over 80% reported being splashed or spilt during preparation or spraying activity. However, we found that the proportion of proper personal protective equipment (PPE) use in our subjects was low. Higher volume of mixture applied (p <  0.001) and broader acres of land (p = 0.001) were associated with higher cumulative exposure level, while using long-sleeved clothes and long pants (p <  0.05) during pesticide spraying were associated with lower cumulative exposure after adjusted for age and gender.

Conclusions

These findings indicate an inadequate knowledge of using pesticides properly. Thus, we recommend comprehensive training on pesticide usage and encourage proper PPE to reduce the exposure level.

Selected Insect Pests of Economic Importance to Brassica oleracea, Their Control Strategies and the Potential Threat to Environmental Pollution in Africa

The most common destructive insect pests affecting cabbages in African smallholder farmers include Plutella xylostella, Helula undalis, Pieris brassicae, Brevycoryne brassicae, Trichoplusia ni and Myzus persicae. Those insect pests infest cabbages at different stages of growth, causing huge damage and resulting into huge yield losses. The African smallholder farmers use cultural and synthetic pesticides to control insect pests and minimize infestations. The cultural practices like crop rotation, weeding and handpicking are used to minimize the invasion of cabbage pests. However, those practices are not sufficiently enough to control cabbage insect pests although they are cheap and safe to the environment. Also, the African smallholder famers rely intensively on the application of broad-spectrum of synthetic pesticides to effectively control the cabbage pests in the field. Due to severe infestation of cabbages caused by those insects, most of African smallholder farmers decide to; first, increase the concentrations of synthetic pesticides beyond the recommended amount by manufacturers. Secondly, increase the rate of application of the synthetic pesticides throughout the growing season to effectively kill the most stubborn insect pests infesting cabbages (Brassica oleracea var. capitata). Thirdly, they mix more than two synthetic pesticides for the purpose of increasing the spectrum of killing the most stubborn insect pests in the field. All those scenarios intensify the environmental pollution especially soil and water pollution. Moreover, most of insecticides sprayed are made with broad-spectrum and are hazardous chemicals posing environmental pollution and threats to natural enemies’ ecosystems. Therefore, this paper reviews Brassica oleracea var. capitata insect pests and control measures as a potential environmental pollution threat in African smallholder farmers.

Pesticide Poisoning and the Use of Personal Protective Equipment (PPE) in Indonesian Farmers

This study aimed to investigate the poisoning symptoms occurring in pesticide-exposed farmers. This study was conducted in a red onion farming center area in Wanasari Subdistrict, Brebes, Indonesia, from May to June 2018. This study was designed as the descriptive study. The significance value of p < 0.005 showed that the variable was correlated with the health problems, including excessive fatigue (p value = 0.041), excessive saliva (p value = 0.006), hard breathing (p value = 0.021), frequent urination (p value = 0.047), blurred vision (p value = 0.059), dizziness (p value = 0.032), and finger pain (p value = 0.007). The significance value (p < 0.005) of 0.000 showed that the use of personal protective equipment was correlated with the health problems. Based on the odds ratio value of 1.137, 95% confidence interval = 0.042-0.444 meant that the personal protective equipment was a risk factor of health problems. The results showed that 89.2% of the farmers who used the personal protective equipment were categorized in the healthy group.